Effects of tank color on body color change, astaxanthin content, and antioxidant capacity of the giant river prawn (Macrobrachium rosenbergii)

Given the importance of tank color in crustacean aquaculture, optimizing the tank color to enhance body color and antioxidant capacity of juvenile giant river prawns (Macrobrachium rosenbergii) is a progressive idea. To explore suitable aquaculture tank colors, we investigated the growth performance, antioxidant capacity, color parameters, pigment cells, and astaxanthin content of juvenile M. rosenbergii reared in different colored tanks (black, white, red, blue, and green). Significant differences in the growth performance of M. rosenbergii reared in different colored tanks were not detected. The superoxide dismutase activity in the hepatopancreas of prawns reared in black, white, and green tanks was higher compared to that of prawns reared in red and blue tanks, and catalase activity in the black and green tank groups was significantly higher than that in the blue tank group (P < 0.05). The redness and yellowness values of prawns reared in black tanks were higher compared to those in the other groups. Optical microscopy observations revealed a higher dispersion of pigment cells in the muscles of M. rosenbergii reared in black tanks. Additionally, the astaxanthin content in the black tank group was significantly higher than that in the other groups (P < 0.05). Correlation analysis indicated a significant negative correlation between the lightness value of the tank color and the redness value of the cooked shell (15 days: r = –0.882, P = 0.000; 30 days: r = –0.752, P = 0.001). In conclusion, our findings indicate that background color significantly affects the antioxidative capability, coloration parameters, and astaxanthin content of M. rosenbergii. Rearing M. rosenbergii in black tanks may represent an effective strategy to optimize its coloration parameters and enhance stress resistance, thereby promoting better aquaculture efficiency and economic returns.